The father of a schoolgirl killed in a bomb blast that hit a school broke down in tears during a church service in her honour.

Devestated Massimo Bassi couldn't control his grief during the funeral mass for 16-year-old Melissa.

She was killed and ten others injured when two powerful explosions went off outside a school in the southern Italian town of Brindisi.

Scroll down for video

Devastated: Melissa Bassi's father Massimo Bassi breaks down during during a mass at a church in Brindisi today after the bomb blast that claimed his daughters life yesterday

Tragic: Police are no longer linking the mafia to a school explosion which killed Massimo Bassi's 16-year-old daughter Melissa on Saturday

Release: CCTV image issued on Sunday night by Italian police of a man wanted in connection with the bomb attack outside a school in Brindisi in which 16-year-old Melissa Bassi was killed

Two powerful explosions scattered deadly shrapnel across a wide area just as students were arriving for lessons as the devices, connected to gas canisters and hidden in rucksacks went off.

Melissa Bassi, 16, suffered horrific injuries in the explosion and was rushed to hospital but died a short while later from her injuries.

There were fears over another of those hurt, a girl, whose condition was described as 'life threatening.'

Tragic: Melissa Bassi, 16, suffered horrific injuries in the explosion and was rushed to hospital but died a short while later from her injuries

Paramedics and police were immediately at the scene and TV footage showed scenes of chaos as shocked students gathered outside the building.

Investigators initially linked organised crime to the blast, close to the Morvillo Falcone school in Brindisi.

The town is home to the local mafia known as the United Sacred Crown who have close links with the Russian and Albanian crime and are linked to drug and gun running.

The school is named after Francesca Morvillo Falcone, who was the wife of anti mafia judge Giovanni Falcone, who were both killed in a bomb blast in 1992 which was carried out by the Sicilian Mafia.

But today a senior official said the attack was probably carried out by a lone individual and played down earlier suspicions of mafia involvement.

A CCTV image of a man wanted in connection with the attack was issued by police on Sunday evening.

Rescue: A woman receives first aid after the explosion outside Francesca Morvillo Falcone high school

Panic: Emergency services and passers-by rush to help those injured in the blast

Brindisi chief prosecutor in charge of the investigation said it now appeared unlikely that either the Sicilian Mafia or the United Sacred Crown, were involved.

Marco Dinapoli said: 'The most probable hypothesis is that it was an isolated act. It seems improbable, not entirely to be excluded, that it is connected with mafia networks.

He also said that attacks on other schools appeared unlikely and that police already had a facial composite picture of a suspect connected to the blast.

Suspicions of mafia involvement were fed not only by the fact that the school was named after the wife of a murdered anti-mafia judge, but also by the timing.

The attack took place days before the 20th anniversary of the couple's death in a bomb attack in Sicily.

Thousands took to the streets in demonstrations of sympathy and outrage at the mafia on Saturday - but Dinapoli said it was still unclear what had prompted the attack.

He said investigators had acquired 'significant' video evidence that suggested one man had set off the device which exploded as pupils were getting off a bus for the start of lessons on Saturday morning.

The footage showed a man of about 50 years of age activating a remote control to detonate a rudimentary bomb made of three gas canisters hidden in a container outside the school gates, he said.

'It could be a person who feels at war with the world. It could be someone who wants to create tension for some ideological reason,' Dinapoli said.

Mourning: Flowers are placed outside the school in Brindisi where the blast happened

Tributes: Dozens of Melissa Bassi's friends have left tributes on her Facebook page

The devices were hidden in a bin about 30metres from the Brindisi courthouse and as they exploded students arriving for lessons caught the full impact of the blasts.

Debris was scattered over a wide area with shrapnel from the canisters piercing shutters of nearby shops and blowing out windows of apartment buildings overlooking the scene.

TV footage showed scenes of desperation as shoes and rucksacks were scattered over the floor, abandoned by the students as the bombs went off just as students arrived for lessons.

Although security across Italy has been stepped up with fears of anarchist attacks due to the drastic economic situation the theory quickly gathering momentum was a never before heard of attack on innocent schoolchildren by the mafia.

Demonstration: Local residents protest the explosion near the high school today

Blame: Brindisi's mayor, Mimmo Consales, accused the mafia or carrying out the attack, but officials later ruled out organised criminal involvement in the attack

Concealed: The devices were hidden in a bin about 30m from the Brindisi courthouse

One eye witness who works in the court building which overlooks the school told Italian media: 'I was just opening the window when the blast caught me in full.

'When I looked down I saw all the kids on the floor, they were covered in black and their books were on fire. It was an infernal scene. Who could have done something like this ? They were just kids.'

Prime Minister Mario Monti cut short a visit to the United States to return home to cope with the aftermath of both the attack and an earthquake in northern Italy in which at least six people died.

In shocked Brindisi, a port town on Italy's Adriatic coast where ferries leave for Greece, photographs of a smiling Melissa were posted around the city and businesses carrying signs declaring they were in mourning.

People placed flowers at police barriers around the 1970s-era school where pupils study fashion, tourism and social services.

Devastating: Shrapnel pierced shutters of nearby shops as the blast blew out windows of apartments

Blast: Two powerful explosions scattered deadly shrapnel across a wide area just as students were arriving for lessons at Morvillo Falcone school

Another girl injured in the attack, Veronica Capodieci, has been transferred to a hospital in the larger city of Lecce.

She is still in serious condition, but the hospital reported on Sunday that she was stable and had regained consciousness.

The deadly attack on a group of young students was shock the whole country at a time when it is already grappling with economic unrest and political scandals.

Franco Scoditti, the mayor of Melissa's home town of Mesagne, near Brindisi, said: 'The school is a symbol of innocence and hope.

'The moment a school is attacked you have to ask yourself where things are heading.'

Shocked: One eyewitness said: 'It was an infernal scene. Who could have done something like this? They were just kids'

Investigation: Italian firefighters inspect the site where an explosive device went off